auto_reset.h

// Copyright (c) 2009 The Chromium Authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file.#ifndef BASE_AUTO_RESET_H_#define BASE_AUTO_RESET_H_#include "base/basictypes.h"// AutoReset is useful for setting a variable to some value only during a// particular scope. If you have code that has to add "var = false;" or// "var = old_var;" at all the exit points of a block, for example, you would// benefit from using this instead.//// NOTE: Right now this is hardcoded to work on bools, since that covers all the// cases where we've used it. It would be reasonable to turn it into a template// class in the future.class AutoReset {
public:
explicit AutoReset(bool* scoped_variable, bool new_value)
: scoped_variable_(scoped_variable),
original_value_(*scoped_variable) {
*scoped_variable_ = new_value;
}
~AutoReset() { *scoped_variable_ = original_value_; }
private:
bool* scoped_variable_;
bool original_value_;
DISALLOW_COPY_AND_ASSIGN(AutoReset);
};
#endif // BASE_AUTO_RESET_H_